Page:
Home > Technical Chat > Can I have some help with some CR maths please.

Supercharger

User Avatar

89 Posts
Member #: 7165
Advanced Member

Solihull/Birmingham

2nd Mar, 2010 at 09:50:26pm

I know this subject has been covered a number of times before, but I'm obviously doing something wrong when I try to use previous guides to work out my CR. So can I be cheeky and ask you more experienced bunch to have a go and see what you come up with.

1293 turbo engine, with CAM6581 crank
Omega 15cc pistons
BK450 hed gasket 3.8 cc I believe ?.
24 cc in the head.




Joe C

User Avatar

12307 Posts
Member #: 565
Carlos Fandango

Burnham-on-Crouch, Essex

2nd Mar, 2010 at 10:11:27pm

I make it 8.4:1, assuming the pistons are flush with the block.



On 28th Aug, 2011 Kean said:
At the risk of being sigged...

Joe, do you have a photo of your tool?



http://www.turbominis.co.uk/forums/index.p...9064&lastpost=1

https://joe1977.imgbb.com/



01smartc

400 Posts
Member #: 2563
Senior Member

Tamworth

2nd Mar, 2010 at 11:30:30pm

Yep I make it 8.4 aswell :)


Rob H

4314 Posts
Member #: 700
Formerly British Open Classic

The West Country

3rd Mar, 2010 at 12:03:10am

As above assuming pistons are flush with the top on the block and ringlan volume is 0.75cc

Isambard Kingdom Brunel said:
Nothing is impossible if you are an Engineer

Supercharger

User Avatar

89 Posts
Member #: 7165
Advanced Member

Solihull/Birmingham

3rd Mar, 2010 at 01:12:01pm




On 2nd Mar, 2010 mini13 said:
I make it 8.4:1, assuming the pistons are flush with the block.





Hi, I will double check they are, but if memory serves me correct, there might be 1mm ish between the top of the piton and the block. Would this make a huge difference ?. Hopefully it will play to my favour and lower it a bit right ?, as the engine will run a supercharged and 8.2.1 ish seems to be spot on. Chances are I will run a charge cooler, so if it's a touch higher that will compensate for it.


Joe C

User Avatar

12307 Posts
Member #: 565
Carlos Fandango

Burnham-on-Crouch, Essex

3rd Mar, 2010 at 01:31:41pm

yep 1mm will make quite a difference,

without checking (dont have my calculator handy) i'm sure it will drop it to below 8:1

On 28th Aug, 2011 Kean said:
At the risk of being sigged...

Joe, do you have a photo of your tool?



http://www.turbominis.co.uk/forums/index.p...9064&lastpost=1

https://joe1977.imgbb.com/


Home > Technical Chat > Can I have some help with some CR maths please.
Users viewing this thread: none. (+ 1 Guests)  
To post messages you must be logged in!
Username: Password:
Page: